defmodule Ammoprices.Scraping.Retailers.TargetSportsUsa do
  @moduledoc false
  @behaviour Ammoprices.Scraping.Scraper

  alias Ammoprices.Scraping.TextDetector

  @slug_to_path %{
    "9mm-luger" => "/9mm-luger-ammo-c-51.aspx",
    "45-acp" => "/45-acp-auto-ammo-c-70.aspx",
    "380-acp" => "/380-acp-auto-ammo-c-50.aspx",
    "40-sw" => "/40-sw-ammo-c-59.aspx",
    "38-special" => "/38-special-ammo-c-56.aspx",
    "357-magnum" => "/357-magnum-ammo-c-57.aspx",
    "10mm-auto" => "/10mm-auto-ammo-c-60.aspx",
    "223-rem" => "/223-remington-ammo-c-83.aspx",
    "556-nato" => "/556mm-nato-ammo-c-2719.aspx",
    "308-win" => "/308-winchester-ammo-c-101.aspx",
    "762x39" => "/762x39mm-ammo-c-108.aspx",
    "30-06" => "/30-06-springfield-ammo-c-105.aspx",
    "300-blackout" => "/300-aac-blackout-ammo-c-969.aspx",
    "65-creedmoor" => "/65-creedmoor-ammo-c-776.aspx",
    "22-lr" => "/22-long-rifle-ammo-c-202.aspx",
    "22-wmr" => "/22-wmr-ammo-c-203.aspx",
    "17-hmr" => "/17-hmr-ammo-c-198.aspx",
    "12-gauge" => "/12-gauge-shotgun-ammo-c-747.aspx",
    "16-gauge" => "/16-gauge-shotgun-ammo-c-748.aspx",
    "20-gauge" => "/20-gauge-shotgun-ammo-c-749.aspx"
  }

  @impl true
  def retailer_slug, do: "target-sports-usa"

  @impl true
  def category_url(caliber) do
    Map.get(@slug_to_path, caliber.slug)
  end

  @impl true
  def parse_products(html) do
    html
    |> Floki.parse_document!()
    |> Floki.find("ul.product-list > li")
    |> Enum.map(&parse_item/1)
    |> Enum.reject(&is_nil/1)
  end

  defp parse_item(item) do
    with {:ok, title} <- extract_title(item),
         {:ok, url} <- extract_url(item),
         {:ok, price_cents} <- extract_price(item),
         {:ok, ppr_cents} <- extract_price_per_round(item) do
      %{
        title: title,
        url: url,
        price_cents: price_cents,
        price_per_round_cents: ppr_cents,
        brand: extract_brand(item),
        grain_weight: extract_grain_weight(title),
        round_count: extract_round_count(title),
        casing: TextDetector.detect_casing(title),
        subsonic: TextDetector.detect_subsonic(title),
        in_stock: extract_in_stock(item)
      }
    else
      _ -> nil
    end
  end

  defp extract_title(item) do
    case Floki.find(item, "h2") do
      [{_, _, _children} = h2] ->
        # Full h2 text minus the <strong> brand text
        full_text = h2 |> Floki.text() |> String.trim()

        brand_text =
          case Floki.find(item, "h2 > strong") do
            [{_, _, _} = strong] -> strong |> Floki.text() |> String.trim()
            _ -> ""
          end

        title =
          full_text
          |> String.replace(brand_text, "")
          |> String.trim()

        if title == "", do: :error, else: {:ok, title}

      _ ->
        :error
    end
  end

  defp extract_url(item) do
    case Floki.find(item, "a") do
      [{_, attrs, _} | _] ->
        case List.keyfind(attrs, "href", 0) do
          {"href", href} -> {:ok, href}
          _ -> :error
        end

      _ ->
        :error
    end
  end

  defp extract_price(item) do
    case Floki.find(item, ".product-listing-price") do
      [{_, _, _} = node | _] ->
        text = node |> Floki.text() |> String.trim()

        case Regex.run(~r/\$([0-9,]+\.\d{2})/, text) do
          [_, amount] ->
            cents =
              amount
              |> String.replace(",", "")
              |> String.to_float()
              |> Kernel.*(100)
              |> round()

            {:ok, cents}

          _ ->
            :error
        end

      _ ->
        :error
    end
  end

  defp extract_price_per_round(item) do
    case Floki.find(item, ".product-listing-price span") do
      [{_, _, _} = node | _] ->
        text = node |> Floki.text() |> String.trim()

        case Regex.run(~r/\$([0-9.]+)\s*Per Round/i, text) do
          [_, amount] ->
            cents =
              amount
              |> String.to_float()
              |> Kernel.*(100)
              |> round()

            {:ok, cents}

          _ ->
            :error
        end

      _ ->
        :error
    end
  end

  defp extract_brand(item) do
    case Floki.find(item, "h2 > strong") do
      [{_, _, _} = strong] ->
        strong
        |> Floki.text()
        |> String.trim()
        |> String.replace(~r/\s*(Ammunition|Ammo)\s*$/i, "")
        |> String.trim()

      _ ->
        nil
    end
  end

  defp extract_grain_weight(title) do
    case Regex.run(~r/(\d+)\s*[Gg]rain/i, title) do
      [_, weight] -> String.to_integer(weight)
      _ -> nil
    end
  end

  defp extract_round_count(title) do
    case Regex.run(~r/(\d[\d,]*)\s*[Rr]ounds?/i, title) do
      [_, count] -> count |> String.replace(",", "") |> String.to_integer()
      _ -> nil
    end
  end

  defp extract_in_stock(item) do
    case Floki.find(item, ".add-to-cart") do
      [{_, _, _} = node] ->
        text = node |> Floki.text() |> String.trim()
        text == "Add To Cart"

      _ ->
        false
    end
  end
end